Bearing



y 14, 1942- A. F. UNDERWOOD 2,289,572

BEARING Filed July 2, 1941 COPPER 5 IL VER 3maentor Patented July 14,1942 signal-teachers! Mich, a corporation of Delaware Detroit,

Application July aim, Serial No. mass '1 cum This invention relates toplain bearings. Such bearings usually fall from either fatigue or scorvIn an ideal bearing installation for a'revolving shaft, the highest oilfilm pressure should occur at the middle of the length of the bearingwhere the bearing has, or should have, the greatest strength. Inpractice, however, due to misalignment of the shaft in its bearing, thehighest oil film pressure frequently occurs in a smaller load supportingoil illmarea towards the end, or at the very edge, of the bearing whereit is weaker than at the middle of its length. When this is the case,failure from either fatigue or scoring is much sooner likely to occur.

Attempts have been made to ensure that the greatest pressure is borne atthe middle of a bearing by increasing the clearance between a shaft andits bearing from the middle thereof towards its ends, by making thebearing with a tapered bore so that it is bell-mouthed. It is, however,diflicult to obtain the correctly tapered bellmouthed contour of thebearing surface for any particular installation.

The object of the present invention is a bearing of increased life, wtiha straight bearing surface which is more readily comformable towards itsends.

The above and other objects of the invention will be apparent as thedescription proceeds.

The drawing shows diiferent examples of bearing construction accordingto the invention.

- In the drawing:

Figure 1 is a perspective view of a half bearing shell according to theinvention.

Figure 2 is an enlarged perspective view of part of Figure 1. n

Figure 3 is a view similar to Figure 2 of a modification of theinvention.

Figure 4 is a view similar to Figure 2 of another modification of theinvention.

'The bearingsshown in the drawing are all steel backed, and theirantifriction linings have a straight bearing surface which graduallyincreases in thickness from the middle of the bearing towards its ends.

The steel back of the bearing of Figures 1 and 2 has a surface adjacentits lining of antifriction material which is crowned or arched. Thelining of antifriction material (babbitt) has a straight bearing surfacelengthwise of the hearing and hence gradually increases in thicknessfrom the middle towards its ends. For example, the thickness of thebabbitt at the middle of the bearing mightbe .002" to .004" increasingto, say. .007" to .011" at its ends.

'fhebearingofl 'lgureahasa-layerofbearing material of sintered coppernickel interposed between a lining of softer antifrictionmaterlalandasteelback. Inthiscasethe sintered copper-nickel, bonded tothe steel back, has a surface adJacent its lining of antifrictionmaterial which is crowned or arched. The copper-nickel is preferablysintered in the crowned surface shape but it may be rolled to this formafter sintering.

The bearing of Figure 4 is agrid type bearing of copper or silver bondedto a steel back. It has an embossed "gridded surface produced by astraight roller with increasingly deeper and coarser grids orinterstices towards its ends. A lining of softer antifrictionv material(babbitt) is applied to the embossed surface of the bearing, filling theinterstices.

As shown in all the examples illustrated, the lining of antifrictionmaterial has a straight bearing surface and gradually increases inthickness from the middle of the bearing towards its ends, although theactual thickness required is less in the copper-nickel bearings becausethe copper-nickel bearing material itself has a greater degree ofconformability than steel.

It will be appreciated that bearings according to the invention havemaximum strength at their middle and maximum conformability at theirends, which will insure that the load of a shaft on such bearings is amaximum at their middle of maximum strength despite any misalignment ofthe shaft in such bearings.

I claim:

1. A plain bearing for a shaft, said bearing being provided with alining of conformable antifriction material supported throughout itslength, and of which the thickness gradually increases from the middleof the bearing towards its ends to constitute a bearing of maximumstrength at its middle'and maximum conformability at its ends, therebyinsuring that the load of said shaft on the bearing is a maximum at itsmiddle of maximum strength despite any misalignment of the shaft in itsbearing.

2. The combination according to claim 1 in which the hearing has a steelback which has a crowned surface adjacent its lining of antifrictionmaterial which has a straight bearing surface.

3. A plain bearing for a shaft, said bearing having a layer of suitablebearing material interposed between a lining of softer antifrictionmaterial and a backing for the bearing: said bearing material having acrowned surface ad- Jacent the lining which has a straight bearingsurface for the shaft.

4. The combination according to claim 3 in which "the bearing materialis copper-nickel bonded to a steel backing, and-the antii'riction liningis Babbitt metal.

5, A plain bearing for a shaft, said bearing being of the grid type witha layer oi suitable bearing material havingan embossed surface to whicha softer antiiriction material is applied.

. filling the interstices, said bearing material being Babbitt metal.

AR'I'HUR F. mmmwoon.

